"Theory of Colloid and Interfacial Electric Phenomena" is written for scientists, engineers, and graduate students who want to study the fundamentals and current developments in colloid and interfacial electric phenomena, and their relation to stability of suspensions of colloidal particles and nanoparticles in the field of nanoscience and nanotechnology. The primary purpose of this book is to help understand how the knowledge on the structure of electrical double layers, double layer interactions, and electrophoresis of charged particles will be important to understand various interfacial electric phenomena and to improves the readers skill and save time in the study of interfacial electric phenomena. It also provides theoretical background and interpretation of electrokinetic phenomena and many approximate analytic formulas describing various colloid and interfacial electric phenomena, which will be useful and helpful to understand these phenomena analyse experimental data. It shows the fundamentals and developments in the field. It is the first book to describe electrokinetics of soft particles. It provides theoretical background and interpretation of electrokinetic phenomena.